utctime in query_images_by_program is wrong

[geoffreymo]

The utctime key in the response for winter.query_images_by_program() is wrong. Here's an example:

For /data/loki/data/winter/20240528/diffs/WINTERcamera_20240529-101849-022_mef_6_0_0_stack.resamp.diff.fits, the MJD in the header is 60459.42973405, which corresponds to

>>> Time(60459.42973405, format='mjd').isot
'2024-05-29T10:18:49.022'

This is consistent with the time provided in the filename. However, the utctime in the query_images_by_program call is 2024-05-29T17:18:49.022000+00:00.